Added

• support for nested commands with action-handlers ([#1] [#764] [#1149])
• .addCommand() for adding a separately configured command ([#764] [#1149])
• allow a non-executable to be set as the default command ([#742] [#1149])
• implicit help command when there are subcommands (previously only if executables) ([#1149])
• customise implicit help command with.addHelpCommand() ([#1149])
• display error message for unknown subcommand, by default ([#432] [#1088] [#1149])
• display help for missing subcommand, by default ([#1088] [#1149])
• combined short options as single argument may include boolean flags and value flag and value (e.g.-a -b -p 80 can be written as-abp80) ([#1145])
• .parseOption() includes short flag and long flag expansions ([#1145])
• .helpInformation() returns help text as a string, previously a private routine ([#1169])
• .parse() implicitly usesprocess.argv if arguments not specified ([#1172])
• optionally specify where.parse() arguments "from", if not following node conventions ([#512] [#1172])
• suggest help option along with unknown command error ([#1179])
• TypeScript definition forcommands property ofCommand ([#1184])
• exportprogram property ([#1195])
• createCommand factory method to simplify subclassing ([#1191])

Fixed

• preserve argument order in subcommands ([#508] [#962] [#1138])
• do not emitcommand:* for executable subcommands ([#809] [#1149])
• action handler called whether or not there are non-option arguments ([#1062] [#1149])
• combining option short flag and value in single argument now works for subcommands ([#1145])
• only add implicit help command when it will not conflict with other uses of argument ([#1153] [#1149])
• implicit help command works with command aliases ([#948] [#1149])
• options are validated whether or not there is an action handler ([#1149])

Changed

• Breaking.args contains command arguments with just recognised options removed ([#1032] [#1138])
• Breaking display error if required argument for command is missing ([#995] [#1149])
• tighten TypeScript definition of custom option processing function passed to.option() ([#1119])
• Breaking.allowUnknownOption() ([#802] [#1138])
  • unknown options included in arguments passed to command action handler
  • unknown options included in.args
• only recognised option short flags and long flags are expanded (e.g.-ab or--foo=bar) ([#1145])
• Breaking.parseOptions() ([#1138])
  • args in returned result renamedoperands and does not include anything after first unknown option
  • unknown in returned result has arguments after first unknown option including operands, not just options and values
• Breaking.on('command:*', callback) and other command events passed (changed) results from.parseOptions, i.e. operands and unknown ([#1138])
• refactor Option from prototype to class ([#1133])
• refactor Command from prototype to class ([#1159])
• changes to error handling ([#1165])
  • throw for author error, not just display message
  • preflight for variadic error
  • add tips to missing subcommand executable
• TypeScript fluent return types changed to be more subclass friendly, returnthis rather thanCommand ([#1180])
• .parseAsync returnsPromise<this> to be consistent with.parse() ([#1180])
• update dependencies

Removed

• removed EventEmitter from TypeScript definition for Command, eliminating implicit peer dependency on@types/node ([#1146])
• removed private functionnormalize (the functionality has been integrated intoparseOptions) ([#1145])
• parseExpectedArgs is now private ([#1149])

Migration Tips

If you use.on('command:*') or more complicated tests to detect an unrecognised subcommand, you may be able to delete the code and rely on the default behaviour.

If you useprogram.args or more complicated tests to detect a missing subcommand, you may be able to delete the code and rely on the default behaviour.

If you use.command('*') to add a default command, you may be be able to switch toisDefault:true with a named command.

The new version differs by 53 commits.

• 2aad525Update dependencies (#1214)
• f86d878Add cli keyword (#1213)
• 83af0fdPrepare for 5.0.0 (#1211)
• f14df07Add eslint settings for TypeScript (#1205)
• 95e0d195.0.0-4
• bd5a49eAdd factory to CHANGELOG
• 8c3dd6fcreateCommand factory routine (#1191)
• 3c9f33fSay we support LTS, so do not need to update when node changes (#1204)
• 3cf8cffExpand typescript checks (#1198)
• a3f453f5.0.0-3
• 87bfca6Add CHANGELOG entries for 5.0.0-3
• 1757564Use a tidier global command (#1200)
• 0a50bd6Add program to exports (#1195)
• 77e511fEnable TypeScript checking of javascript, and resolve or suppress errors (#1194)
• 2491c76URLEncode several chinese toc link

There are 53 commits in total.

See thefull diff